MyBatis-statement方式的增删改查

复习第一个Mybatis程序
0.mybatis.jar ojdbc.jar
1.conf.xml(数据库配置信息+映射文件)
2.表-类映射文件
3.测试类

mybatis约定:
输入参数parameterType和输出参数resultType只能有一个

如果输入参数:是简单类型(八个基本类型+String) ，则可以使用任何占位符
如果是对象类型，则必须是对象得属性#{属性名}

输出参数:如果返回值类型是一个对象(如Student)，则无论返回一个还是多个
在resultType都是写成org.myy.entity.Student
即resultType="org.myy.entity.Student1"

注意事项；
如果使用的事务方式为JDBC，则需要手工提交，即session.commit();

所有的标签<select><delete>等，都必须有sql语句，但是sql参数值可选

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE mapper 
PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN"
"http://mybatis.org/dtd/mybatis-3-mapper.dtd">

<!--namespace:该mapper.xml映射文件的唯一标识  -->
<mapper namespace="org.myy.entity.studentMapper"><!--映射文件的路径  -->
    <!--后续通过namespace.id  -->
    <!--parameterType:输入参数的类型  
        resultType返回结果值得类型
    -->
    <select id="queryStudentByStuno" parameterType="int" resultType="org.myy.entity.Student1">
        select * from student1 where stuno=#{stuno}
    </select>
    
    <insert id="addStudent" parameterType="org.myy.entity.Student1">
        insert into student1(stuno,stuname,stuage,graname) values(#{stuNo},#{stuName},#{stuAge},#{graName})
    </insert>
    
    <delete id="deleteStudentByStuno" parameterType="int">
        delete from student1 where stuno=#{stuno}
    </delete>
    
    <update id="updateStudentByStuno" parameterType="org.myy.entity.Student1">
        update student1 set stuname=#{stuName},stuage=#{stuAge},graname=#{graName} where stuno=#{stuNo}
    </update>
    
    <select id="queryAllStudent" resultType="org.myy.entity.Student1">
    select * from student1
    </select>
</mapper>

test.java

package org.myy.entity;

import java.io.IOException;
import java.io.Reader;
import java.util.List;

import org.apache.ibatis.io.Resources;
import org.apache.ibatis.session.SqlSession;
import org.apache.ibatis.session.SqlSessionFactory;
import org.apache.ibatis.session.SqlSessionFactoryBuilder;

public class Test {
    //查询单个学生
    public static void queryStudentByStuno() throws IOException {
        //Connection - SqlSession操作Mybatis
                //conf.xml->reader
                Reader reader = Resources.getResourceAsReader("conf.xml");
                //reader->sqlSession
                
                //可以通过build的第二参数 指定数据库环境
                SqlSessionFactory sessionFactory=new SqlSessionFactoryBuilder().build(reader,"development");
                SqlSession session = sessionFactory.openSession();
                
                String statement="org.myy.entity.studentMapper.queryStudentByStuno";
                Student1 student1 = session.selectOne(statement,1);
                System.out.println(student1);
                session.close();
    }
    //查询全部学生
    public static void queryAllStudent() throws IOException {
        //Connection - SqlSession操作Mybatis
                //conf.xml->reader
                Reader reader = Resources.getResourceAsReader("conf.xml");
                //reader->sqlSession
                //可以通过build的第二参数 指定数据库环境
                SqlSessionFactory sessionFactory=new SqlSessionFactoryBuilder().build(reader,"development");
                SqlSession session = sessionFactory.openSession();
                
                
                String statement="org.myy.entity.studentMapper.queryAllStudent";
                List<Student1> student1s=session.selectList(statement);
                System.out.println(student1s);
                session.close();
    }
    //增加学生
    public static void addStudent() throws IOException {
        //Connection - SqlSession操作Mybatis
                //conf.xml->reader
                Reader reader = Resources.getResourceAsReader("conf.xml");
                //reader->sqlSession
                //可以通过build的第二参数 指定数据库环境
                SqlSessionFactory sessionFactory=new SqlSessionFactoryBuilder().build(reader,"development");
                SqlSession session = sessionFactory.openSession();
                
                
                String statement="org.myy.entity.studentMapper."+ "addStudent";//statement:指定执行的sql
                Student1 student1=new Student1(3,"myy",200,"yym");
                int count = session.insert(statement, student1);
                session.commit();//提交事务
                System.out.println("增加"+count+"个学生");
                session.close();
    }
    //删除学生
    public static void deleteStudentByStuno() throws IOException {
        //Connection - SqlSession操作Mybatis
                //conf.xml->reader
                Reader reader = Resources.getResourceAsReader("conf.xml");
                //reader->sqlSession
                //可以通过build的第二参数 指定数据库环境
                SqlSessionFactory sessionFactory=new SqlSessionFactoryBuilder().build(reader,"development");
                SqlSession session = sessionFactory.openSession();
                
                
                String statement="org.myy.entity.studentMapper."+ "deleteStudentByStuno";//statement:指定执行的sql
                int count = session.delete(statement, 3);
                session.commit();//提交事务
                System.out.println("删除"+count+"个学生");
                session.close();
    }
    //修改学生
        public static void updateStudentByStuno() throws IOException {
            //Connection - SqlSession操作Mybatis
                    //conf.xml->reader
                    Reader reader = Resources.getResourceAsReader("conf.xml");
                    //reader->sqlSession
                    //可以通过build的第二参数 指定数据库环境
                    SqlSessionFactory sessionFactory=new SqlSessionFactoryBuilder().build(reader,"development");
                    SqlSession session = sessionFactory.openSession();
                    
                    
                    String statement="org.myy.entity.studentMapper."+ "updateStudentByStuno";//statement:指定执行的sql
                    //修改的参数
                    Student1 student1=new Student1();
                    //修改哪个人
                    student1.setStuNo(2);
                    student1.setStuName("lss");
                    student1.setStuAge(9);
                    student1.setGraName("ss");
                    int count = session.update(statement, student1);
                    session.commit();//提交事务
                    System.out.println("修改"+count+"个学生");
                    session.close();
        }
    public static void main(String[] args) throws IOException {
        queryStudentByStuno();
        addStudent();
        queryAllStudent();
        deleteStudentByStuno();
        queryAllStudent();
        updateStudentByStuno();
        queryAllStudent();
    }
}